Fig. 5

NOD2 alleviates pathological changes in mouse osteoarthritis model. A Safranin O/fast green staining of knee joints after intra-articular injection (scale bar = 100 μm). B Micro-CT scanning and 3D reconstruction of knee joints after intra-articular injection. C IHC staining of knee joints after intra-articular injection (scale bar = 100 μm). D OARSI score indicating cartilage injury and its mitigation by oe-NOD2 lentiviral injection. E, F Quantitative analysis of micro-CT shows osteophyte formation and attenuation by oe-NOD2. G, K Intensity score analysis of IHC staining demonstrating the impact of oe-NOD2 on synovial tissue and articular cartilage. K–M Association of interrupted M1 phenotype transition with the alleviation of osteoarthritis by NOD2 overexpression. *p < 0.05, **p < 0.01, and ***p < 0.001. Data were presented as boxplots (center line, median; box limits, 25 to 75th percentiles; whiskers, min to max) (n = 6 for each group). Kruskal–Wallis test followed by Dunn’s multiple comparisons test for multi-group comparisons of OARSI scores, osteophytes and ODS scores of IHC images